1. Field of the Invention
This invention relates to a device for piling bound sets of sheets in which a sequence of such sets are formed into a pile with their bindings offset from the core of the pile so the pile stays stable.
2. Prior Art
U.S. Pat. No. 4,369,015, Fabrig, whose disclosure of a book turning device is incorporated herein by reference, produces a series of bound sets of sheets, also denoted as blocks in the following text, with the bindings lying alternately in front and behind. Such devices have been known since the year 1961, and commercialised by bielomatik Leuze GmbH+Co. of 7442 Neuffen, West Germany, in their machine type P 248.
In the use of such a machine, the blocks, with their bindings lying alternately in front and behind, are fed to the region of the pile and a controllable stop ensures that the bindings, which are thicker than the thickness of the rest of the block, project out over the core of the pile. The term pile core denotes that part of the pile in which the actual sets of sheets without the bindings lie on top of one another. The pile core can be thought of as limited on both sides by a pile edge which is constituted by the joining line of the front edges, i.e. those edges lying opposite the binding, of alternate blocks in the pile. The controllable stop has the effect that the blocks, depending upon the position of the bound edge, are forwarded more or less further into the pile region before they are deposited on the block located below. This device is relatively complex. It requires the mechanical outlay for the movement of the controllable stop and additionally an electrical or electronic control means. A sinking pile table must be used because of the type of piling.
Nevertheless, such procedures must be undertaken since otherwise the bindings, the diameter of which is greater than the thickness of the block, would come to lie otherwise relative to the blocks lying below and above it and thereby would form a thicker, unwieldy and insecurely packed pile which would be in danger of toppling. Additionally, the bindings would mark the sheet sets during packing and transport and it could even happen, with pressure on the pile, that the bindings, for example spiral bindings, would distort.